The second preseason game for the San Francisco 49ers against the Los Angeles Chargers was another opportunity for players to strengthen their standing on the team.Time is running out for those who need to impress the coaches to retain a roster spot or rise up on the depth chart. With that said, here are the five 49ers whose stock increased the most against the Chargers.Kaelon BlackThis game was the first time anyone besides reporters and some fans at training camp got to see a glimpse of rookie Kaelon Black. And boy, did he impress a bit.Black showcased great toughness and power. He may not be very fast and shifty, but he's a great change of pace from Christian McCaffrey.There's no shying away from contact for Black. This is exactly the style of running back the 49ers have needed when they're faced with a few yards or less to convert a play.Sincere McCormickProbably the biggest surprise from the game was running back Sincere McCormick. Usually, there isn't much hope for a player when he's signed in the Summer (McCormick signed Jun. 10).However, McCormick gave much to like about his status on the team. He carried the ball six times for 53 yards with one enormous 37-yard run.His stats were solid, but that's not what increases his stock. Similar to Black, it's about how hard he ran and how smooth he looked. The 49ers coaches have to be considering retaining him now.Jacob CowingPersonally, I was writing off Jacob Cowing already as a player who wasn't going to make the team. I thought that before training camp started. However, he threw himself a lifeline in this game.Cowing took an 83-yard punt return to the house. Kyle Shanahan admitted his return helped his stock, so it'll serve as a stepping stone to a bigger role in the preseason finale.Jaden DuggerThere weren't as many plays that rookie Jaden Dugger made against the Chargers as he did against the Titans. But he was still impressive.The one play he made that stood out the most was in pass coverage. Dugger kept up with tight end Oronde Gadsden in coverage, who's a fairly fast player.Dugger didn't cause a pass breakup, and he did bite on what looked like a fake screen, but his athleticism showed up to recover and almost stay stride-for-stride. His traits continue to pop off the screen.Garrett WallowAnytime the Chargers thought they had a clear rushing lane to execute a modest gain, it was linebacker Garrett Wallow who was there to ruin it.The guy has a nose for the ball. He's going to charge at it and find it. No running back is safe, no matter how clear the rushing lane is.Wallow was also playing in the first half, which shows he's ahead of Tatum Bethune. The stock is going up for Wallow after his performance against the Chargers.Follow Jose on X (Twitter) @JS3sanchezz and his YouTube channel to interact with him on the 49ers and more.Add us as a preferred source on GoogleFollow